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Biomedical subjects

Tao Jin

Publications and source records attributed to Tao Jin.

At least 19 recordsLinked to original sources
PubMed2006

Epsilon aminocaproic acid reduces transfusion requirements in patients with thrombocytopenic hemorrhage.

BACKGROUND: Epsilon aminocaproic acid (EACA) is an antifibrinolytic drug that has been used to control hemorrhage by stabilizing the thrombus. It has been used in thrombocytopenic patients largely on an empiric basis. METHODS: Concerns regarding side effects have limited the use of this drug. The authors reviewed their experience with EACA at the Cleveland Clinic Foundation from 1997 to 2003. RESULTS: Of 77 patients with thrombocytopenic hemorrhage, 51 (66%) patients achieved a complete response and 13 (17%) patients achieved a partial response, resulting in a decrease in platelet and red blood cell transfusions. Adverse effects were manageable in this set of patients with severe underlying disease. CONCLUSIONS: Based on this experience, EACA may be a valuable adjunctive therapy in the treatment of patients with thrombocytopenic hemorrhage.

Adult↗
PubMed2006

Source of nonlinearity in echo-time-dependent BOLD fMRI.

Stimulation-induced changes in transverse relaxation rates can provide important insight into underlying physiological changes in blood oxygenation level-dependent (BOLD) contrast. It is often assumed that BOLD fractional signal change (DeltaS/S) is linearly dependent on echo time (TE). This relationship was evaluated at 9.4 T during visual stimulation in cats with gradient-echo (GE) and spin-echo (SE) echo-planar imaging (EPI). The TE dependence of GE DeltaS/S is close to linear in both the parenchyma and large vessel area at the cortical surface for TEs of 6-20 ms. However, this dependence is nonlinear for SE studies in the TE range of 16-70 ms unless a diffusion-weighting of b = 200 s/mm(2) is applied. This behavior is not caused by inflow effects, T(2)* decay during data acquisition in SE-EPI, or extravascular spin density changes. Our results are explained by a two-compartment model in which the extravascular contribution to DeltaS/S vs. TE is linear, while the intravascular contribution can be nonlinear depending on the magnetic field strength and TE. At 9.4 T, the large-vessel IV signal can be minimized by using long TE and/or moderate diffusion weighting. Thus, stimulation-induced relaxation rate changes should be carefully determined, and their physiological meanings should be interpreted with caution.

Animals↗
PubMed2006

Role of MIB1 in predicting survival in patients with glioblastomas.

BACKGROUND: Histologic immunomarkers of cell cycle proteins have been utilized for prognosis in high-grade astrocytic tumors. One such marker, MIB1, an antibody immunoreactive throughout the cell cycle, is predictive of more aggressive disease and poorer prognosis in astrocytomas. An independent role of MIB1 analysis for survival prediction and clinical management within histologic grades has not been clearly proven. METHODS: This study retrospectively evaluated MIB1 reactivity in tissue samples from 116 patients with glioblastomas on initial medical presentation. Clinical variables considered included gender, age, Karnofsky Performance Scores (KPS), extent of surgical resection, adjuvant radiation and survival. RESULTS: Univariate and multivariate analyses were used to correlate these variables with MIB1 staining. MIB1 staining does not predict overall survival or response to adjuvant therapy as an independent risk factor. CONCLUSION: MIB1 labeling does not predict patient survival as an independent variable and does not predict response to additional therapies. Patient survival with glioblastoma was predicted by KPS, age, extent of resection and use of adjuvant radiotherapy.

Adult↗
PubMed2005

Pattern recognition using asymmetric attractor neural networks.

The asymmetric attractor neural networks designed by the Monte Carlo- (MC-) adaptation rule are shown to be promising candidates for pattern recognition. In such a neural network with relatively low symmetry, when the members of a set of template patterns are stored as fixed-point attractors, their attraction basins are shown to be isolated islands embedded in a "chaotic sea." The sizes of these islands can be controlled by a single parameter. We show that these properties can be used for effective pattern recognition and rejection. In our method, the pattern to be identified is attracted to a template pattern or a chaotic attractor. If the difference between the pattern to be identified and the template pattern is smaller than a predescribed threshold, the pattern is attracted to the template pattern automatically and thus is identified as belonging to this template pattern. Otherwise, it wanders in a chaotic attractor for ever and thus is rejected as an unknown pattern. The maximum sizes of these islands allowed by this kind of neural networks are determined by a modified MC-adaptation rule which are shown to be able to dramatically enlarge the sizes of the islands. We illustrate the use of our method for pattern recognition and rejection with an example of recognizing a set of Chinese characters.

Journal Article↗
PubMed2005

Staphylococcus aureus: Staphylokinase.

Staphylokinase is a 136 aa long bacteriophage encoded protein expressed by lysogenic strains of Staphylococcus aureus. Present understanding of the role of staphylokinase during bacterial infection is based on its interaction with the host proteins, alpha-defensins and plasminogen. alpha-Defensins are bactericidal peptides originating from human neutrophils. Binding of staphylokinase to alpha-defensins abolishes their bactericidal properties, which makes staphylokinase a vital tool for staphylococcal resistance to host innate immunity. Complex binding between staphylokinase and plasminogen results in the formation of active plasmin, a broad-spectrum proteolytic enzyme facilitating bacterial penetration into the surrounding tissues. We have recently shown high levels of staphylokinase expression in clinical isolates of skin and mucosal origin and relative low levels in isolates invading internal organs. These findings are supported by sepsis studies using isogenic S. aureus strains demonstrating increased bacterial load in the absence of staphylokinase production. Our observations indicate that staphylokinase favours symbiosis of staphylococci with the host that makes it an important colonization factor.

Animals↗
PubMed2005

Urokinase-type plasminogen activator, an endogenous antibiotic.

Urokinase-type plasminogen activator (uPA) is a serine protease that not only displays fibrinolytic function but also modulates innate and adaptive immune responses. In the present study, we assessed whether uPA acts as an endogenous antibiotic. It has been demonstrated that uPA inhibits growth of Staphylococcus aureus both in vivo and in vitro. Importantly, the bactericidal properties of uPA are associated with the serine protease domain of the molecule but are not dependent on its plasminogen-activation potential and cannot be inhibited by plasminogen activator inhibitor type 1 (PAI-1). In a murine infection model, uPA treatment alleviated staphylococcal sepsis by inhibiting bacterial growth. To further evaluate the changes in uPA levels during the course of staphylococcal infection, total uPA and active uPA levels were analyzed in plasma and in kidney homogenates. Expression of total uPA was constant, but PAI-1 levels were dramatically increased in plasma and in kidney homogenates during the course of staphylococcal infection. After infection with staphylococci, the level of metabolically active uPA was unaltered in plasma but was significantly decreased in kidney homogenates. Active uPA levels were inversely related to PAI-1 levels and to bacterial loads in kidney homogenates. In conclusion, we report that uPA acts as an endogenous antibacterial substance that might constitute the first line of host defense against staphylococcal infection. The decreased active uPA levels in infected organs might be due to the dramatically increased PAI-1 production during S. aureus infection.

Animals↗
PubMed2005

The role of urokinase in innate immunity against Staphylococcus aureus.

Urokinase (uPA) is a serine protease that not only displays fibrinolytic function but also promotes host leukocytes to home to inflammatory sites. We have recently demonstrated that staphylokinase (SAK), which is a fibrinolytic protein secreted by Staphylococcus aureus, forms complexes with human neutrophil peptides (HNPs), which are members of the defensin family and have anti-microbial properties, thereby inhibiting the bactericidal effects of the HNPs. The aim of this study was to assess whether endogenous uPA, which has fibrinolytic properties similar to those of SAK, binds to HNPs and interferes with SAK/HNPs interaction. To this end, an ELISA was used to analyze the interactions between uPA and HNPs. HMW uPA had the ability to bind to both HNP types. The biological consequences of the formation of this complex were analyzed with respect to its bactericidal properties. HMW uPA killed S. aureus, albeit at relatively high doses (50-100 mug/ml). In contrast, the binding of HMW uPA to HNPs had no impact on the bactericidal functions of the HNPs. Importantly, the addition of HMW uPA to SAK eliminated the ability of SAK to neutralize HNPs. Our results demonstrate that endogenous HMW uPA inhibits S. aureus growth both directly, by cytolysis, and indirectly, by abrogation of the neutralizing effect of SAK on the bactericidal activities of HNPs. These findings indicate novel functions of HMW uPA in the host defense against staphylococcal infections.

Humans↗
PubMed2005

Secondary rupture of aorta following the surgical management of aortoesophageal fistula.

A patient suffering from an aortoesophageal fistula (AEF) caused by a fish bone, was treated in our institute in 2000. The operation was successful and the patient had an uneventful early postoperative course. However, the patient died of frank hematemesis on the 6th postoperative day due to secondary rupture of the aorta. The lessons learnt and surgical efforts to manage AEF caused by an esophageal foreign body are discussed.

Aorta, Thoracic↗
PubMed2005

[Differential display technique and its progress].

Differential display technique is an important method to isolate differentially expressed gene. Comparing to other methods like representational difference analysis, suppression subtractive hybridization and serial analysis of gene expression, differential display technique is used in higher frequency. Since it was established in 1992, it has overcome many disadvantages and widened its practical fields through improvements and enhancements by global researchers. In this paper the principle and the main advantages and disadvantages of differential display technique were briefly introduced. Meanwhile, the four progressed aspects in designing primer, reducing false positives, identifying differentially expressed gene and techniques derived from DD were introduced in detail.

Blotting, Northern↗
PubMed2005

Effects of prostaglandin E1 on the progression of aristolochic acid nephropathy.

OBJECTIVE: To investigate the effects of prostaglandin E1 (PGE1) on the progression of aristolochic acid nephropathy (AAN). METHODS: Twenty-four patients diagnosed as AAN with serum creatinine (Scr) between 1.5 mg/dL and 4 mg/dL during September 2001 to August 2003 were randomly divided into 2 groups. All patients had ingested long dan xie gan wan containing aristolochic acid (0.219 mg/g) for at least 3 months. Twelve patients were injected with Alprostadil (10 microg/d for 10 days in one month, summing up to 6 months). Except for PGE1, the other therapy was same in both groups. Renal function was assessed using reciprocal serum creatinine levels (1/Scr). RESULTS: The level of Scr an d serum hemoglobin (Hgb) was similar in both groups prior to therapy. During follow-up, 1/Scr levels in PGE1 group were significantly higher than control group (P < 0.01), and Hgb levels in PGE1 group were significantly increased compared with control (P < 0.05). CONCLUSION: PGE1 can slow the progression of renal failure and increase Hgb level of AAN patient.

Adult↗
PubMed2005

[Molecular genetic study on patients with lattice corneal dystrophy in China].

OBJECTIVE: To investigate the mutations of the BIGH3 gene in patients with lattice corneal dystrophy in China. METHODS: Molecular genetic analysis was performed on DNA extracted from peripheral leukocytes from eight patients with lattice corneal dystrophy and without systemic amyloidosis in Tongren Ophthalmic Center. Exons 4, 12, 14 of the BIGH3 gene were amplified by polymerase chain reaction and were sequenced directly. The cornea of these patients were examined with slit lamp biomicroscope and photographed. At the same time, 32 normal subjects were recruited in the molecular genetic analysis as the controls. RESULTS: Three LCDI patients had R124C mutation (one missense mutation at position 417 C-->G of exon 4) in the BIGH3 gene, all of them were heterozygous. The other five patients showed different H626R mutations at position 1924 from A to G of the BIGH3 gene in exon 14, all of them were heterozygous too. The clinical appearance in patients with H626R mutation was an intermediate type between LCDI and LCDIII or LCDIIIA. CONCLUSIONS: R124C mutation and H626R mutation are detected in Chinese patients with lattice corneal dystrophy. It seems that H626R mutation not only presents in British and French patients, but also can be found in Asia patients.

Adult↗
PubMed2005

[Study on breeding up high-yield strain of taxol by protoplast mutagensis].

In order to obtain resistant mutants to nystatin, ultraviolet radiation and LiCl were used to mutagenize the protoplasts of taxol-producing fungi NCEU-1, and four positive mutants with high yield of taxol were screened out on nystatin flat. After further screening experiments on fermentation, a mutant strain--UL04-5 which was able to produce taxol with high yield and could be stably passed on in genetics was eventually found, it's ability to produce taxol was improved from 314.07 microg/L (strain NCEU-1) to 418.24 microg/L (strain U04-5).

Ascomycota↗
PubMed2004

Controlling disorder in liquid crystal aerosil dispersions.

The effect of disorder in the behavior of liquid crystal (LC) is assessed and controlled by dispersing known amounts of silica aerosil in the liquid crystal material. Using deuteron nuclear magnetic resonance, the director configuration and the orientational order was determined for hydrophilic aerosil dispersions in octylcyanobiphenyl. The confined liquid crystal exhibits a well-defined alignment as the silica spheres stabilize the molecular configuration. At low silica densities, a silica network is eventually established, forming a soft gel. When the sample orientation in the magnetic field is changed, a few silica strands links are broken and a fraction of the LC molecules is realigned. The field anneals the random disorder introduced by the aerosil up to a certain density beyond which, in the so-called stiff-gel regime, disordering effects completely dominate. At a fixed temperature in the isotropic phase, there is surface-induced order that is linearly proportional to the silica density.

Journal Article↗
PubMed2004

Staphylococcus aureus resists human defensins by production of staphylokinase, a novel bacterial evasion mechanism.

Alpha-defensins are peptides secreted by polymorphonuclear cells and provide antimicrobial protection mediated by disruption of the integrity of bacterial cell walls. Staphylokinase is an exoprotein produced by Staphylococcus aureus, which activates host plasminogen. In this study, we analyzed the impact of interaction between alpha-defensins and staphylokinase on staphylococcal growth. We observed that staphylokinase induced extracellular release of alpha-defensins from polymorphonuclear cells. Moreover, a direct binding between alpha-defensins and staphylokinase was shown to result in a complex formation. The biological consequence of this interaction was an almost complete inhibition of the bactericidal effect of alpha-defensins. Notably, staphylokinase with blocked plasminogen binding site still retained its ability to neutralize the bactericidal effect of alpha-defensins. In contrast, a single mutation of a staphylokinase molecule at position 74, substituting lysine for alanine, resulted in a 50% reduction of its alpha-defensin-neutralizing properties. The bactericidal properties of alpha-defensins were tested in 19 S. aureus strains in vitro and in a murine model of S. aureus arthritis. Staphylococcal strains producing staphylokinase were protected against the bactericidal effect of alpha-defensins. When staphylokinase was added to staphylokinase-negative S. aureus cultures, it almost totally abrogated the effect of alpha-defensins. Finally, human neutrophil peptide 2 injected intra-articularly along with bacteria alleviated joint destruction. In this study, we report a new property of staphylokinase, its ability to induce secretion of defensins, to complex bind them and to neutralize their bactericidal effect. Staphylokinase production may therefore be responsible in vivo for defensin resistance during S. aureus infections.

Adult↗
PubMed2004

Adrenoceptor compounds prevent the settlement of marine invertebrate larvae: Balanus amphitrite (Cirripedia), Bugula neritina (Bryozoa) and Hydroides elegans (Polychaeta).

The effects of the neurotransmitter blockers idazoxan and phentolamine on the larval settlement of three marine invertebrate species belonging to three different phyla were investigated by using in vitro concentration-response bioassays. Since neurotransmitters are known to influence metamorphic transitions in invertebrate larvae, neurotransmitter blockers were tested to evaluated their sublethal effects on larvae. The alpha-adrenergic antagonists idazoxan and phentolamine inhibited settlement of Balanus amphitrite (Cirripedia), Bugula neritina (Bryozoa) larvae, and larvae of the polychaete Hydroides elegans (Polychaeta) in a concentration-and taxon-dependent manner. At concentrations of 10(-3) M of both agents, larvae of all three species became immobile and subsequently died within 24 h. While cumulative settlement rates were observed after 48 h for B. amphitrite and H. elegans, and after 5 h for B. neritina, >90% of the larvae that settled did so within 24 h for the first two species and within 1 h for B. neritina. The tendency of the hydrophobic idazoxan and phentolamine to accumulate at solid surfaces most probably contributes to their successful inhibition of larval settlement. This ability makes them particularly attractive as candidates for the development of slow-release carriers in antifouling paints.

Adrenergic alpha-Antagonists↗
PubMed2004

[Identification of BIGH3 gene mutations in the patients with two types of corneal dystrophies].

OBJECTIVE: To identify the mutations of BIGH3 gene in Chinese patients with corneal dystrophies. METHODS: Polymerase chain reaction in exon 4, exon 12 and direct DNA sequencing of BIGH3 gene were performed in fifteen patients with corneal dystrophies and ten normal individuals as controls. RESULTS: Mutations in BIGH3 gene were detected in all the patients with corneal dystrophies. BIGH3 gene mutations were not found in normal subjects. Twelve patients with Avellino corneal dystrophy had the missense mutation R124H in the BIGH3 gene. Three patients with granular corneal dystrophy had the missense mutation R555W in the BIGH3 gene. CONCLUSION: R124H and R555W mutations in BIGH3 gene were found in the patients with Avellino and granular corneal dystrophies. Avellino corneal dystrophy associated with the R124H mutation is the most common form in the corneal dystrophies resulting from BIGH3 gene mutations. Condons 124 and 555 are also the hot spots for the mutations in the BIGH3 gene in the Chinese patients with corneal dystrophies.

Adolescent↗
PubMed2003

Fatal outcome of bacteraemic patients caused by infection with staphylokinase-deficient Staphylococcus aureus strains.

Staphylokinase (SAK) is a plasminogen-activator protein produced by Staphylococcus aureus. SAK production was evaluated in vitro in S. aureus isolates from the bloodstream of patients with lethal (n = 56) and non-lethal (n = 57) bacteraemia and from anterior nares of healthy subjects (n = 48). Most isolates (93/161) produced SAK, and 68 % of SAK-producing isolates expressed both surface-bound and secreted types of SAK. SAK production was significantly less common among isolates from patients with lethal bacteraemia (39 %) than isolates from patients with non-lethal bacteraemia (68 %) or nasal carriage isolates (67 %) (P < 0.01). After adjusting for infection with methicillin-resistant S. aureus and APACHE II score, patients infected with SAK-deficient isolates were 4.3 times more likely to have lethal bacteraemia than patients whose infecting isolate produced high levels of SAK (> or =5 microg ml(-1)), suggesting that in vitro SAK production was inversely associated with clinical outcome among patients with S. aureus bacteraemia. The high frequency of SAK production in nasal isolates and in cases with uncomplicated bacteraemia suggests that SAK may be one of the adaptive mechanisms of S. aureus symbiosis with the host.

Age Factors↗